Re: [Chrysler300] Sudden drive train lock-up

This is a good point. I could not have moved the car +/- 7 feet without hitting the rear wall and the garage door.I think it was more like 2 or 3 feet I moved before it locked up. But if the input pinion was stopping on something (pin) it wouldn’t even make 1 revolution of the pinion, which might be 1/3 of a tire revolution, which might be just a couple of feet. (It turns freely now continuously in either direction).

Yes, it is limited slip, and that was locked up by sitting a couple of years ago and made a horrible racket when I tried to turn (not unlike this current episode). I drained all the diff oil and put the correct oil in it with Mopar correct (for this limited slip) additive. I took it to a vacant parking lot and turned figure 8’s and it eventually smoothed out and has never been a problem since. That very well could be related. I agree about power testing until I understand the problem. It was suggested that I put it in gear on the jack stands earlier, but I didn’t for that reason. I am confident that although I may have a failure somewhere, I haven’t done anything to break it-yet.

When I get the driveshaft back in, I will try pushing it back and forth and see if it locks up. It did stop squarely in both directions, the rear wheels seemed to lock up simultaneously. I wasn’t moving fast so nothing skidded-it just stopped immediately. Real immediately!

I have both a transmission jack and a floor jack. I am accustomed to using the floor jack for dropping my Jaguar IRS, but this center section is a much smaller chunk so I may have to strap it to the tranny jack.

One revolution of tire would be about 7 feet +/-. So if it goes
about 6 to 7 feet in each direction before locking up, I'd be
looking at something jamming up differential. Maybe less distance
depending on what is broken inside. Is diff Limited Slip? I would be
careful about further diagnostics under power - may do more damage.
Does it happen when rolling car by hand in neutral?

Center chunk can be removed - heavy but can be handled - did it when
I was a kid but would use something to support weight these days -
smarter and not as strong.

If one side only, maybe brake on that side, but I doubt both brakes
would lock up at same point. Push with steering wheel turned - then
repeat opposite direction - is it different left vs right?

If you are ambitious - disconnect drive shaft and push - does it
still lock up - if so you have isolated to diff / axle / rear
brakes. But I'm leaning that way anyway. Broken tooth or pin jammed
in ring gear as someone else suggested would be my bet.

Not
really sure how
your rear is
assembled, but
it sounds like
the center pin
has come loose
in you spider
gears and is
hitting after
one revolution
of the
tires/pinion. Go
forward and it
comes around and
hits again.

When I backed it up, after approx 3
ftthe drive locked up sharply, as though
I had hit
something. But
I hadnâ€™t,
and all 4
wheels were
clear. It did
the same thing
going
forward-locking
up after just
a few feet.I
did this
several times
and the
distances
prior to
lockup seemed
the same.

I was able to give it a lot of gas and
slowly it
would move,
but something
was straining.

This afternoon, after completing new
starter motor
installation,
I dropped the
driveshaft to
have a suspect
rear U-joint
replaced
tomorrow, but
I see nothing
which looked
like it was
hitting.

On jack stands under the axle, I also
am able to
rotate both
rear wheels in
either
direction
continuously
without a lock
up. My next
step is to
remove both
rear drums and
ensure there
are no broken
brake
springs, but
if I donâ€™t
see anything
there, I have
no idea where
to look next.
There are no
unusual noises
when I rotate
the wheels.